In portable radio applications it is typically necessary to provide some form of water intrusion sealing for the internal microphone cartridge which is found within the radio housing. One prior art technique for sealing the microphone is shown in FIG. 1. This prior art technique uses a rubber boot 102 for retaining the microphone cartridge 104 to the radio housing 108. A separate water resistant layer of felt, GORETEX.TM., polyurethane membrane, or other water resistant material 106 is disposed between the rubber boot 102 and radio housing 108 and blocks microphone port 110, in order to protect the microphone cartridge 104 from water intrusion. Both the rubber boot 102 and water resistant layer 106 are attached to radio housing 108 using adhesives or other well known attachment techniques. A set of wires 112 interconnect the microphone cartridge to the radio electronics.
In FIG. 2, a second prior art technique for environmentally protecting the microphone cartridge 206 is shown. In this prior art technique, a rubber boot 208 which is pressure fitted to radio housing holds the microphone cartridge 206 in place. This method also requires that a felt or GORETEX.TM. layer 204 be attached to radio housing 202 between the microphone port and the microphone cartridge 206. Here again, a set of wires 210 interconnect the microphone cartridge to the rest of the radio electronics.
The prior art techniques for sealing an internal microphone as discussed above require a large number of parts and require a great amount of labor which increases the cost of producing a product having an internal microphone, such as a portable two-way radio. A need thus exists in the art for a seal which can provide environmental sealing to the internal microphone cartridge in a cost effective manner.